NBC has continued picking up comedies for next season, renewing Parks and Recreation and freshman entries Whitney and Up All Night, and canceled four first-year scripted series.

As it looks to beef up its comedy ranks ahead of its Monday morning upfront, the ratings-challenged network is filling up its schedule with new and returning half-hour projects. Parks, Whitney and Up join previously renewed Community and 30 Rock at the network.

Here's a look at why the shows were granted renewals:

Parks and RecreationThe Thursday night comedy starring Amy Poehler, Nick Offerman and Aziz Ansari will return for a fourth season of 22 episodes after boosting the network's fortunes in the 9:30 p.m. Thursday slot after its midseason move. The comedy from Mike Schur and created by The Office's Greg Daniels remains a critical darling, with Poehler earning a pair of lead actress Emmy nominations and the series scoring a best comedy nom last year as well.

Up All NightCreated by Parks and Recreation veteran Emily Spivey,the freshman comedy starring Christina Applegate, Will Arnett and Maya Rudolph earned a quick full-season order after opening strong following America's Got Talent. While the series cooled from its bow to a 3.7 rating in the adult demo on Wednesdays, it was a solid performer after being shifted to the prime post-The Office slot on Thursdays midseason. Its April 12 season finale garnered a 1.5 in the demo and 3.1 million viewers, decent by NBC's reduced standards and enough to propel the comedy about new parents to see a second season.

WhitneyCreated by and starring Whitney Cummings, the comedy vehicle came out of the gate strong for a network much in need. But with critics balking and a scheduling switch, the series took a hit. Thus far this season, Whitneyis averaging a 2.2 ratings in the coveted demo. Still, the stand-up comic is 2-for-2 this season with NBC granting a second season to Whitney and CBS has already having renewed the Cummings-produced 2 Broke Girls. What's more, she will soon have a Chelsea Handler-like talk project on E!

Here's a look at what's been canceled:

Harry's LawThe legal drama starring Kathy Bates received a 24-episode order for its sophomore season -- which wraps its run May 20 -- after what sources indicated last May was a swap for the network passing on creator David E. Kelley's Wonder Woman pilot. For its part, the older-skewing Sunday night series remained a solid draw in total viewers for the struggling network at 8 p.m., serving as a lead-in to Celebrity Apprentice.

Are You There, Chelsea?Despite built-in name recognition, the comedy failed to cut through the clutter on Wednesday nights. Based on Handler's outrageous book Are You There, Vodka? It's Me, Chelsea, the series starred Laura Prepon in the title role with Handler recurring as the older sister of the sitcom's Chelsea. Creatively, the midseason entry underwent both cast and executive producer changes behind the scenes just months after it earned a series order. Its March finale drew a 1.2 in the demo and 3 million viewers, despite a lead-in from former Thursday comedy Whitney.

AwakeKyle Killen'sdrama is one-and-done. The dual-universe series about a cop who loses his wife in one realm and his son in another failed to find traction despite critical buzz. After launching to 6 million viewers and a 2.0 in the demo in March, the drama staring Jason Isaacs tumbled to 2.2 million total viewers and a 0.8 in 18-49. The effort was considered a big swing for the broadcast network as critics across the board deemed the series a better fit for cable. Not working in its favor was its hugely competitive time slot at 10 p.m. Thursday against fare including CBS' The Mentalist.

BentThe romantic comedy from Universal Television starring Amanda Peet and David Walton received a quick burn-off on Wednesday nights, completing its six-episode run in just three weeks. Its final episode drew less than 2 million viewers and a 0.7 in the demo. Walton, meanwhile, booked the lead in CBS' untitled Greg Malins/Greg Berlanti comedy opposite Joanna Garcia Swisher.

Best Friends ForeverThe comedy reated by and starring Lennon Parham and Jessica St. Clair bowed in early April to 4 million viewers and a 1.2 rating in the demo. The Universal Television series was yanked from the schedule after four outings.